| 摘要 |
PURPOSE:To make a transmission speed high by regulating position of a phase conjugate element to a position where wavelength dispersion arisen at the upstream side of the phase conjugate element and wavelength dispersion arisen at the downstream side of the phase conjugate element come to be equal. CONSTITUTION:As a modulation method in an optical transmission device 2, for example, it is possible to adopt a strength modulation method. In this case, even when direct modulation of a semiconductor laser which is easy to cause wavelength charping is carried out, it is possible to carry out optical transmission without being influenced by wavelength dispersion. As an optical transmission passage 2, a single mode optical fiber of a quartz group with which propagation loss of light becomes minimum at a wavelength 1.55mum can be used. In this case, it is possible to carry out long distance transmission by way of restraining the propagation loss small by setting the wavelength of an output light from the optical transmission device 2 at 1.55mum band. |
